In recent years, there has been a focus on designing oil or gas wells so complex that it is possible to control the components, such as valves, from surface without having to intervene the well by means of intervention tools. In order to control the components from surface, the completion has been equipped with control lines extending from surface all the way down to the components several kilometres down the well on the outside of the production casing. However, the control lines thus have to extend past the main barriers, which induces a substantial risk of leaking barriers and thus the possibility of blowouts.
To prevent having control lines, some wells have been developed with a much simpler design without control lines. These wells of a more simple design are much quicker to complete, meaning that substantial rig time is saved. In order to adjust e.g. the valves of wells having such simple well design, intervention tools are used. However, some operators still want to have wells completed without the use of intervention tools.